/*
 * Copyright 2015-2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.hawkular.apm.server.api.utils.zipkin;

import java.util.List;

import org.hawkular.apm.server.api.model.zipkin.Span;

/**
 * Class for deriving various information from {@link Span}.
 *
 * @author Pavol Loffay
 */
public class SpanDeriverUtil {

    private SpanDeriverUtil() {}

    /**
     * Derives an operation from supplied span.
     *
     * @param span the Span
     * @return operation (e.g. HTTP method)
     */
    public static String deriveOperation(Span span) {
        if (SpanHttpDeriverUtil.isHttp(span)) {
            return SpanHttpDeriverUtil.getHttpMethod(span);
        }
        return span.getName();
    }

    /**
     * Derives fault from Span. Fault is determined by HTTP client/server error code contained in binary annotations.
     *
     * @param span the span
     * @return fault ()
     */
    public static String deriveFault(Span span) {
        List<SpanHttpDeriverUtil.HttpCode> errorCodes =
                SpanHttpDeriverUtil.getClientOrServerErrors(SpanHttpDeriverUtil.getHttpStatusCodes(span.getBinaryAnnotations()));

        if (errorCodes.size() > 0) {
            return errorCodes.iterator().next().getDescription();
        }

        return null;
    }

}
